This invention relates to improvements in a vessel for transporting floatable buoyant cargo units in which the buoyancy of the cargo is in part transferred to support a substantial portion of the transporting vessel's own weight. More particularly, this invention relates to a vessel with engageable hinged swash bulkheads for impeding the sloshing of water within the flooded hold of the vessel when it is carrying fewer buoyant cargo units than its full load capacity of such cargo units.
In vessels of the type utilizing the present invention, the hull structure serves to contain a predetermined number of cargo units secured by a locking mechanism and at the same time to provide a smooth external envelope of a desired form to minimize hydrodynamic resistance. At the same time, the hull enables employment of the buoyancy of the cargo units by always maintaining a flooded cargo hold which is common with the waterway or sea. This may be done, for example, by means of permanent openings in the bottom of the hull for free passage of water in and out. Such a type of vessel is more particularly described in our copending application Ser. No. 511,492, now U.S. Pat. No. 3,913,512, issued Oct. 21, 1975.
From time to time during the operations of such a vessel there may not be a full complement of cargo units for transport on a given voyage, and a lower-than-capacity number of cargo units will then be loaded and secured therein. Without a full complement of cargo units, a free surface of unrestrained water will then be present in the flooded hold. In such a partly loaded situation the cargo units actually present in the hold may become subjected to severe and even destructive pressures from the sloshing effect of water induced by the pitching and other movements of the vessel during its voyage. The present invention is directed to the protection of the cargo units from such sloshing water forces in this situation.